Exponential growth

Can anyone help me with a problem for my physics lab? We are studying capacitance and I'm not even sure what this problem has to do with it. I think you're supposed to use a log or ln, but I never had calculus, so I don't think you're supposed to do it that way. Any help would be appreciated!

The yearly growth rate of the US is 1 percent. Assuming this growth rate to be constant, in how many years will the population double?

Here's how I would do that problem: Saying that the annual growth rate is 1% means that the population, P, increases by .01P each year or to 1.01P each year: the population is multiplies by 1.01 each year so the formula is P(t)= P0(1.01)t. The population will have doubled when P(t)= 2P0= P0(1.01)t or 2= (1.01)t.

Taking logs of both sides, log(2)=tlog(1.01) or t=log(2)/log(1.01).

In Chroot's method, k= ln(1.01) so this is, in fact, exactly the same answer. (I used log instead of ln because any base will do.)